I own a Late-2007 White MacBook and I more or less clean the outside of it about once a month. However, in the past some of my old laptops had died due to heat issues, and on one, it was due to the fan dying. My cousin, who's had similar issues with laptops, introduced me to a method he used to clean the inside of his laptop. He'd take a vacuum cleaner with a hose attachment and put the end right up to the exhaust port of the system fan. He'd turn it on and use a can of compressed air/dust remover spray to blow air into the laptop through whatever orifice (Optical Drive, intake ports, etc) so that any dust thrown up by the compressed air would be sucked up by the vacuum. Now after all the months of owning my MacBook, I'd never done it. And living in Manila, as any asthmatic will tell you, the air is filled with particulate matter. So, yesterday I decided to clean the inside of my MacBook, but with an added step. I used the disassembly guide from the folks at ifixit.com to disassemble my MacBook so I could clean it thoroughly (I just followed the Logic Board Replacement instructions for the MacBook Core 2 Duo up to Step 12 only.) It's fairly simple, although it may be daunting for someone who's not used to tinkering with computer innards. And there is one part where you have to pry up your keyboard topcase with a little force in order to separate it from the chassis. Anyways, I followed the guide and here's what I found: You can't really see it, but it really was grimy inside. With the following picture, you can really see the dirt. Right under the main dirty area was the cooling fan. So you can see that the cooling intake is thru/between the keys in the keyboard. So keep that area clean. And you can see why using a keyboard cover without holes can lead to temperature problems. Keep those screws organized so you can remember where they go when you reassemble it. Tools of the trade for cleaning. Vacuum with hose attachment and a can of compressed air. Like I said, it was grimy on the inside. Not too bad at first glance. But with the first puff of compressed air I blew a huge cloud of dust that the vacuum subsequently sucked up. This happened again when I used the can to blow through the exhaust ports at the screen hinge. I also used a microfiber cloth to clean the underside of the keyboard topcase for whatever the vacuum/compressed air couldn't get: After cleaning the inside, I reassembled the system and used some iKlear to clean the screen and a 3M Magic Sponge to clean the case & keyboard. I'll probably be good for another 2 years without cleaning the inside.